JAVMANewsSubsection

Substitution errors

Surveys describe harm from differences between prescriptions and drugs dispensed

By Greg Cima

Posted Aug. 20, 2014

Updated Sept. 4, 2014

Ten percent of veterinarians responding to recent polls said they have had patients harmed when outside pharmacies made substitutions in filling prescriptions.

Surveys conducted by five veterinary medical associations together indicate about one-third of respondents knew of occasions when pharmacies dispensed drugs to clients that were different from those that were prescribed or were different in dosage, and they did so without consulting the prescribing veterinarian. Most of those changes occurred without any known harm.

The Oregon, Idaho, Iowa, and Washington veterinary medical associations conducted their surveys in 2012, and the Southern California VMA conducted its survey in 2013. They received responses from 707 veterinarians.

Those veterinarians provided examples­­—included in reports from the VMAs—such as replacement of a prescribed insulin product with one less effective in dogs, a recommendation that a client administer aspirin to a cat rather than pay for a prescription nonsteroidal anti-inflammatory drug, and reduction of a dog’s thyroid medication dosage that seemed high to the pharmacist in comparison with the dosage for humans.

Glenn Kolb, executive director of the Oregon VMA, which conducted the first survey, said veterinarians had been asking the association how to respond when they find out about substitutions. While he acknowledged that pharmacists need to counsel clients, it seems to him that some have altered prescriptions for animals on the basis of uses in human medicine.

Jennifer Davis, PharmD, president of the Oregon State Pharmacy Association, noted that a pharmacist can work with hundreds of patients in a typical week. While the Oregon VMA asked veterinarians whether they had encountered a change in a prescription at some point, she noted that the survey did not ask how many times such problems occurred.

“The error rate based on those thousands of interactions is exceptionally low,” she wrote in a message. “None-the-less, we accept that every error is significant and continually work on processes and knowledge that can minimize the likelihood of an error.”

Study and response in Oregon

Dr. Laird M. Goodman, owner of Murrayhill Veterinary Hospital in Beaverton, Ore., said a client told him she cut an epileptic dog’s phenobarbital dosage in half on advice from a pharmacist who thought the dosage was high. The dog’s seizures returned and could not be controlled, leading to a decision to administer euthanasia.

He also has seen alterations to patients’ thyroid medication prescriptions.

“We do need to work on opening stronger communications between pharmacists and veterinarians. Pharmacists take their responsibility as the last check in drug review and distribution seriously but need to follow up with veterinarians if they have questions. We hope that veterinarians will be equally open to working with pharmacists as they fulfill their professional responsibilities.”

Jennifer Davis, PharmD, president,

Oregon State Pharmacy Association

“In the good old days, they would at least call us and say, ‘Hey, are you sure you want to give this high of a dose?’” Dr. Goodman said. “And we would advise the pharmacist that dogs take a higher dose than people.”

Gary Miner, RPh, compliance director for the Oregon Board of Pharmacy, expects that changes without consultation occur no more often in veterinary medicine than in human medicine, where they are rare. Over the past few years as the board has raised awareness among pharmacists about the need for consultation on veterinary prescriptions, he said, “They’re probably more cautious about filling veterinary prescriptions than they are the human prescriptions,” although he hopes pharmacists provide the same due diligence for both.

Prior to the surveys, the Oregon Board of Pharmacy and the state’s two pharmacy schools had been in talks about increasing pharmacy students’ education on veterinary pharmacy. Fiona Karbowicz, RPh, a consultant to the Oregon pharmacy board, said veterinary pharmacy has not been a substantial part of pharmacists’ education, yet pharmacists are filling increasing numbers of veterinary prescriptions.

“We saw the need to get more education out there in a variety of different ways,” she said.

Oregon’s pharmacy board has advocated that pharmacists and pharmacy technicians be mindful when filling veterinary prescriptions, and the board has given pharmacy students and pharmacist associations presentations that included information on veterinary prescriptions, Karbowicz said. The board also requires that pharmacies dispensing veterinary drugs have references such as Plumb’s Veterinary Drug Handbook or the Merck Veterinary Manual.

The Oregon State Pharmacy Association also has worked to improve the “critical link in patient care” between veterinarians and pharmacists by providing continuing education on veterinary pharmacy, Dr. Davis said. And she noted that an increasing number of U.S. pharmacists are completing residency training in veterinary pharmacies.

“We do need to work on opening stronger communications between pharmacists and veterinarians,” Dr. Davis said. “Pharmacists take their responsibility as the last check in drug review and distribution seriously but need to follow up with veterinarians if they have questions.

“We hope that veterinarians will be equally open to working with pharmacists as they fulfill their professional responsibilities.”

Kolb said representatives from the Oregon VMA and state pharmacy board have talked about the issue over the past two years, and the OVMA has developed information sheets for veterinarians to give to clients when writing prescriptions to be filled by outside pharmacies. He thinks changes in the absence of consultation are less common than before the OVMA conducted its survey.

Accidents, intent, and generics

Miner suspects that some of the Oregon VMA survey respondents who reported knowing of unauthorized changes were referring to instances when clients received generic rather than name-brand drugs.

If a veterinarian writes “no substitution” or “dispense as written,” a pharmacist cannot provide an equivalent without the veterinarian’s authorization.

He also said the Oregon VMA did not give details that would have let the board investigate incidents reported in the survey.

The board has been receiving more reports of errors since the survey, Miner said, although most are related to accidental changes rather than deliberate substitutions. Such mistakes are unfortunate but normal occurrences in pharmacies, he said.

Karbowicz said a 2013 investigation found, for example, that an Oregon pharmacy made a decimal point–related error rather than an intentional substitution in filling a prescription for a pet’s thyroid medication at 0.05 mg rather than the prescribed dose of 0.5 mg, although the former would be a more typical dose for humans. The board imposed a $1,000 ine.

“We are initiating an investigation for each and every call that we get­,” she said.

But Karbowicz, who previously worked in retail pharmacy, expects almost no pharmacist would intentionally dispense medication differing from a prescription without consulting the prescriber.

“I’m very appreciative of the surveys because they have brought the conversation forward,” she said. “And the

conversation clearly showed that education and more awareness was needed around the whole topic, especially as it’s just grown over the past, maybe 10 years, or so.”

But she said the survey results need to be substantiated, and the limited data available are not alarming.

Concern among VMAs

Candace Joy, executive vice president of the Washington State VMA, said her association's survey, patterned after the Oregon VMA’s, indicated it is commonplace, in her words, “to have pharmacists switching drugs, altering dosages, changing quantities without any authorization from the prescribing veterinarian.” Her organization presented their survey findings to the Washington State Pharmacy Quality Assurance Commission.

The results, described in a January 2013 report, showed that most pharmacists call the prescribing veterinarian when they have questions or concerns. But they also show “an alarming trend in recurring problems by pharmacists unfamiliar with veterinary pharmacology and physiology” as well as problems related to an inadequate supply of veterinary drugs.

“Pharmacists are not specifically trained in veterinary pharmacology and physiology and are making the assumption that animals respond to drugs similarly to humans,” the report states. “Cats and dogs are not small humans and species variability in the metabolism of drugs is significant.”

“If it’s happening this much in our two states, I know that it’s happening everywhere.”

Given the survey results from Oregon and Washington, Joy said such changes in veterinary prescriptions are a national issue.

“If it’s happening this much in our two states, I know that it’s happening everywhere,” she said.

Dr. Peter Weinstein, executive director of the Southern California VMA, which also based its survey on Oregon's, wants

veterinarians to follow up on filled prescriptions and ensure that clients are receiving the intended products. He also advocates that veterinarians have working relationships with pharmacies.

He said that, as more clients receive prescriptions from pharmacists, organized veterinary medicine should find a way

to benefit pets, pet owners, and veterinarians.

“I think that there has to be a way that we can all benefit from this and not end up in a contentious battle,” he said.

“It’s just going to change the way we think about conducting our businesses.”

Correction: An earlier version of this article included an inaccurate statement that pet owners in Oregon could, by requesting generic alternatives, override a veterinarian’s orders against substitutions.